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virtual particle

n. (context physics English) a particle that exists for a limited time and space, introducing uncertainty in their energy and momentum

Virtual particle

In physics, a virtual particle is a transient fluctuation that exhibits many of the characteristics of an ordinary particle, but that exists for a limited time. The concept of virtual particles arises in perturbation theory of quantum field theory where interactions between ordinary particles are described in terms of exchanges of virtual particles. Any process involving virtual particles admits a schematic representation known as a Feynman diagram, in which virtual particles are represented by internal lines.

Virtual particles do not necessarily carry the same mass as the corresponding real particle, although they always conserve energy and momentum. The longer the virtual particle exists, the closer its characteristics come to those of ordinary particles. They are important in the physics of many processes, including particle scattering and Casimir forces. In quantum field theory, even classical forces — such as the electromagnetic repulsion or attraction between two charges — can be thought of as due to the exchange of many virtual photons between the charges.

The term is somewhat loose and vaguely defined, in that it refers to the view that the world is made up of "real particles": it is not; rather, "real particles" are better understood to be excitations of the underlying quantum fields. Virtual particles are also excitations of the underlying fields, but are "temporary" in the sense that they appear in calculations of interactions, but never as asymptotic states or indices to the scattering matrix. As such the accuracy and use of virtual particles in calculations is firmly established, but their "reality" or existence is a question of philosophy rather than science.

Antiparticles have been proven to exist and should not be confused with virtual particles or virtual antiparticles.

Usage examples of "virtual particle".

Paul's captor, constructed of the Virtual particle sets of the seething vacuum, resembled its forebears - the odd, vast creatures who had spawned as constructs of convection cells in a boiling ocean - as a laser rifle resembles a piece of chipped stone.

In effect, you're a large virtual particle that has tunneled out of the quantum foam.

The explanation of how black holes can emit particles and radiation (given in Chapter 7) was that one member of a virtual particle/ antiparticle pair (say, the antiparticle) might fall into the black hole, leaving the other member without a partner with which to annihilate.

It is therefore possible, if a black hole is present, for the virtual particle with negative energy to fall into the black hole and become a real particle or antiparticle.

As the two spacecraft neared the point where signaling from future to past became possible, the transit time for the loop would approach zero, and each virtual particle would find an exponentially growing army of doppelgangers hard on its heels: future versions of itself which had already made the trip.

Paul's captor, constructed of the Virtual particle sets of the seething vacuum, resembled its forebears&mdash.

Relativity demanded that a free-falling particle's rotating phase agree with every other clock that travelled the same path, and once gravitational time dilation was linked to changes in virtual particle density, every measure of time —.

Though I'll ask the others about virtual particle transient barrier, whatever.

With catlike eyes, he observed the construction on the southern cap of the seventh chamber, radiating for kilometers outward from the bore hole, huge black concentric rings of virtual particle stimulators and their reservoirs of graviton-stabilized tritium metal.

The launch from White Sands transformed us from a virtual particle into a virtual wave, firing us out of the pit like a bullet from a gun.

Restraints on Probabilities of atomic positions may induce an alignment Of virtual Particle activities, with amplification of other quantum effects, including remote release of quantum information normally communicated between particles and inaccessible to non-communicants.

He was gone, a virtual particle in motion, and the port and starboard walls were glowing bright orange with the heat of the momentum exchange.